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A219988
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Number of tilings of a 5 X n rectangle using dominoes and right trominoes.
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2
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1, 0, 24, 140, 2319, 21272, 262191, 2746048, 31411948, 342302244, 3830482893, 42241878920, 469601959777, 5197411955932, 57664560160890, 638914582091712, 7084373947760105, 78520055192688696, 870480364546718647, 9649003719594586976, 106963676725852631636
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OFFSET
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0,3
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LINKS
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FORMULA
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G.f.: see Maple program.
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MAPLE
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gf:= (2*x^18 +52*x^17 -358*x^16 +1396*x^15 -3682*x^14 +4644*x^13 -2629*x^12 -1426*x^11 +906*x^10 +4146*x^9 -2315*x^8 -2804*x^7 +4106*x^6 -1636*x^5 +245*x^4 +178*x^3 -52*x^2 -6*x +1) /
(20*x^19 +216*x^18 -2920*x^17 +8422*x^16 -13616*x^15 +5915*x^14 +4330*x^13 +4832*x^12 -10814*x^11 +482*x^10 +15910*x^9 -17717*x^8 +1636*x^7 +6151*x^6 -2722*x^5 +590*x^4 +182*x^3 -76*x^2 -6*x +1):
a:= n-> coeff (series (gf, x, n+1), x, n):
seq (a(n), n=0..30);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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